ctlmod.py

   1 # Erebus IRC bot - Author: John Runyon
   2 # module loading/unloading/tracking code
   3
   4 import sys
   5 import modlib
   6
   7 modules = {}
   8 dependents = {}
   9
  10 def isloaded(modname): return modname in modules
  11 def modhas(modname, attname): return getattr(modules[modname], attname, None) is not None
  12
  13 def load(parent, modname):
  14         if not isloaded(modname):
  15                 sys.path.insert(0, 'modules')
  16                 try:
  17                         mod = __import__(modname)
  18                         reload(mod) #in case it's been previously loaded.
  19                 except BaseException as e: #we don't want even sys.exit() to crash us (in case of malicious module) so use BaseException
  20                         return modlib.error(e)
  21                 finally:
  22                         del sys.path[0] #remove ./modules from path, in case there's a name conflict
  23
  24
  25                 if not hasattr(mod, 'modinfo'):
  26                         return modlib.error('no modinfo')
  27
  28                 if parent.APIVERSION not in mod.modinfo['compatible']:
  29                         return modlib.error('API-incompatible')
  30
  31                 modules[modname] = mod
  32                 dependents[modname] = []
  33
  34                 for dep in mod.modinfo['depends']:
  35                         if dep not in modules:
  36                                 depret = load(parent, dep)
  37                                 if not depret:
  38                                         return
  39                         dependents[dep].append(modname)
  40
  41
  42                 ret = mod.modstart(parent)
  43                 if ret is not None and not ret:
  44                         del modules[modname]
  45                         del dependents[modname]
  46                         for dep in mod.modinfo['depends']:
  47                                 dependents[dep].remove(modname)
  48                 return ret
  49         else: #if not isloaded...else:
  50                 return modlib.error('already loaded')
  51
  52 def unload(parent, modname):
  53         if isloaded(modname):
  54                 for dependent in dependents[modname]:
  55                         unload(parent, dependent)
  56                 for dep in dependents[modname]:
  57                         dependents[dep].remove(modname)
  58                 ret = modules[modname].modstop(parent)
  59                 del modules[modname]
  60                 return ret
  61         else:
  62                 return modlib.error('already unloaded')
  63
  64 def reloadmod(parent, modname):
  65         if isloaded(modname):
  66                 if modhas(modname, 'modrestart'): modules[modname].modrestart(parent)
  67                 else: modules[modname].modstop(parent)
  68
  69                 try:
  70                         reload(modules[modname])
  71                 except BaseException as e:
  72                         return modlib.error(e)
  73
  74                 if modhas(modname, 'modrestarted'): ret = modules[modname].modrestarted(parent)
  75                 else: ret = modules[modname].modstart(parent)
  76
  77                 return ret
  78         else:
  79                 return load(parent, modname)
  80
  81
  82 def loadall(parent, modlist):
  83         for m in modlist: load(parent, m)
  84 def unloadall(parent, modlist):
  85         for m in modlist: unload(parent, m)
  86 def reloadall(parent, modlist):
  87         for m in modlist: reloadmod(parent, m)
  88
  89 sys.path.append('modules')